Friction-latch for levers.



J. F. HOWIE.

FRICTION LATCH FOR LEVERS.

APPLICATION FILED AUG. 11, 1913.

1,175,868.. Patented Mar. 14, 1916.

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FRICTION LATCH FOR LEVERS.

APPLICATXON FILED AUG.H, 1913.

1,175,868. Patented Mar. 14, 1916.

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JAMES F. HOWIE, OF SEATTLE, WASHINGTON.

FRICTION-LATCH FOR LEVEBS.

Specification of Letters Patent.

Patented Mar. 14, 1916..

v 2 Application filed August 11, 1913. Serial No. 784,098.

To all whom it may concern Be it known that 1, JAMES F. HOWIE, a citizen ofthe United States of America, and a resident of the city of Seattle, in the county of King and State of Washington, have invented certain new and-useful 1m? rovements in Friction-Latches for Levers, of which the following is a specification.

My invention pertains to a device of the above character capable of fine adjustment and it has for an object to provide such a means which will operate in an eflicient man ner and be of simple and durable construcion.

A further object resides in the mounting of the grippers which permits the latter to grip effectively at all timeseven though irregularities incident to wear may occur on the gripping face of the quadrant or sector.

Other objects will appear as my description progresses, and those features of construction, arrangements and combinations of parts on which protection is desired sue-- cinctly defined in the appended claims.

'For a full understanding of the invention, reference is had to the following description and the accompanyingdrawings wherein,

Figure 1, illustrating the lever embodying my invention applied to the boiler of a locomotive for controlling the throttle valve; Fig. 2, is an enlarged view of the lever with parts broken away; Fig. 3 is a'front elevation thereof with parts in section, Fig. 4 is an enlarged fragmentary elevation partly in section disclosing more clearly the gripping rollers which are, in this instance, in an inoperative position; Fig. 5 is a sectional view on line 55 of Fig. 4; Fig. 6 discloses my invention slightly modified for application to the reverse lever of a locomotive; Fig. 7 is an enlarged fragmentary elevation thereof; and Fig. 8 is a vertical sectional view of the modification.

. Referring in detail to the drawings, wherein like characters of reference denote like parts throughout the several views, 1 designates a support, which may be the boiler of a locomotive, 2 the throttle valve stem 3 the quadrant or sector and 4 the throttle lever pivoted to the quadrant, as at 5, and having its fulcrum pivot 6 on the outer. end portion of a vibratory link 7, the opposite end portion of which latter being pivoted to an ear 8 outstanding from the ;1 upport 1.

The gripping face 3 of the quadrant is smooth and is received between the lever and a spaced parallel guide 4 integrally formed on the lever. The quadrant, with the exception of the smooth face 3, and the lever are of usual construction, the valve stem 2 being fastened in the socket 3 of the quadrant member 3.

The lever is provided with a transverse opening 9 and a longitudinally arranged slot 10, opening into the opening or slot 9. Within the transverse slot are arranged a pair of friction gripping rollers 11 which are connected by links 12 to a pin or shaft 13, mounted in a transverse slot 14 of block: 15, the latter being slidable in longitudinal slot 10.

An expansion spring 16 in the longitudinal slot of the lever tends to move the block toward the slot 9 and thereby forcing the rollers 11 for effective engagement between the quadrant between the quadrant face 3 and the inclined faces 9 of the slot 9. In this connection it will be noted that the faces 9 are inclined from slot 10 toward the quadrant whereby any relative movement of the lever and quadrant will only tend to more efiectively grip the rollers between the faces 3 and 9.

Links 17 connect pin 13 to latch 18, whereby on moving the rollers 11 will be freed from the quadrant as shown in Fig. 4, said links 17 also forming guides for the spring 16 and block 15.

The slot 14 in the block 15 permits of independent movement of the rollers, that is,

should one roller engage between the faces 3 and 9 before the other roller grips the latter will continue to move, under the influence of the spring 16, until it engages between its respective face 9' and quadrant face 3. This is especially advantageous if the faces 9 are not exact, and also in the event one side wears more rapidly than the other.

In the modification, the lever 20 has its end slotted to receive pivot pin 21 of support 22 while a connecting rod 23 connects said lever to the reversing mechanism of the locomotive '(not shown). The quadrant or sector 24, mounted on support 22, is gripped by friction rollers 11 which, as in the first mentioned construction, are connected to pin 13 by links 12 and are retracted by latch 18 connected to the pin by links 17.

The lever is slotted to permit of the quadrant expanding and contracting as influenced by the heat of the nearby locomotive boiler (not shown) and, therefore, to prevent longitudinal movement of the lever away from the quadrant when the gripping rollers are applied, a roller bearing 25 is carried by the lever for engaging the under side of the quadrant.

The guide 26 of the lever is extendedand provided with a slot 27 registering with a similar slot 28 in the lever body, both of which open into transverse slot 9 and are disposed approximately opposite the slot 10 in which the spring 16 and block 15 operate. The roller bearing is inserted between the body proper of the lever and guide 26, the trunnions or'stubs 29 of the bearing journaling in the-slots 27 and 28, most clearly shown in Fig. 8.

While I have referred to my invention as being applied to locomotive levers, it is of course, understood that the invention may be embodied and applied to other types of levers without departing from the spirit of the invention.

'Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the, United States of America is '1. A lever locking device. comprising a pivoted lever, a sector fixed at the pivot of said lever and provided with a convex gripping face, a transverse slot in said lever having an edge opposing the grippingface of the sector, this edge being inclined from the center inboth directions toward the gripping face of the sector, gripping members in said slot, said gripping members being operatively joined to move simultaneously, means tending to push said grip- L ping members toward the ends of the slot in the lever to thereby lock said lever, and means for" pulling said gripping members toward the center of the slot, to release said lever.

2. A lever locking 'device comprising a pivoted lever, a sector. fixed at the pivot of said lever and provided with a convex gripping face, a transverse slot in. said lever having an edge opposing the gripping face of the sector, this edgebeing inclined from the center in both directions toward thegripping face of the sector, gripping mem bers in said slot, said gripping members be ing operatively joined by pivoted links forming a toggle lever construction, a releasing rod secured at the common pivot of said links, and a spring tending to urge said gripping members toward the .outer end of pivoted lever, a sector fixed at the pivot of said lever and provided with a convex gripping face, a transverse slot in said lever having an edge opposing the gripping face of the sector, this edge being inclined from the center in both directions toward the gripping face of the sector, gripping mem bers in said slot, a block slidable longitu-' dinally of saidlever, links pivoted to said gripping members and to said block, a spring acting upon said block to thereby push said gripping members to the outer ends of the" slot in the lever, and a releasing rod secured to said block.

, 4. A lever locking device comprising a pivoted lever, a sector fixed at the pivot of said lever, said sector having a smooth gripping face, a transverse slot in said lever having an edge opposing the gripping face of the sector and adjacent thereto, this ed e being inclined from the center in both i rections toward the gripping face of the sector, a block having a transverse slot therein and slidable on said lever, a pin in said slot, gripping rollers in said slot in the lever and pivotally secured to said pin,

spring means tending to urge said block toward the sector, to thereby spread said gripping rollers, and means for moving said block away from the sector.

5. A lever locking device comprising a pivoted lever, a sector fixed at the-pivot of spring in said longitudinal'slot tending to urge said block toward thesector, to thereby spread said gripping rollers, and a rod connected to said block to move said block away from the sector.

' Signed at Seattle, Washington, this'5th day of August 1913.

JAMES F. HOWIE.

Witnesses: MONCRIEFFE CAMERON,

CLARA A. HARM.

v said lever, said sector having a smooth gripping roller in said transverse slot in thelever at each side of said block, links pivoted to said pin and to said rollers, an extension 

